Answer on Electromagnetism Question for Chelsea

2017-03-20T18:53:44-0400

Question #66515

You have taken physics and you know that household circuits usually have circuitbreakers limiting current to 20 A or less. You also know that pacemakers can beinfluenced by external electric or magnetic fields. If a pacemaker is safe for magneticfields of 1 mT and below, how close can someone wearing a pacemaker get to a wireinside of a home?

Expert's answer

2017-03-24T15:55:07-0400

The induction of the infinite conductor is divided as B = mm0*I/2*3.14*R. Thus, R = mm0*I/2*3.14*B = 4*10^-3 m or 4 mm. You actually cannot use pacemaker closer than 4 mm out of the wire with 20 A.